Tuck-forming mechanism for sewing-machines.



J. E. CHALMAN. TUCK FORMING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED JUNE 11, 1915. 1 ,227, 1 1 6. Patented May 22, 1917.

2 SHEETS-SHEET 1.

l. E. CHALMAN.

TUCK FORMWG MECHANRSM FOR SEWtNG MACHINES. APPLICATION FILEID JUNE u. 1915.

I 1,227,1 16. Patented May 22,1917.

2 SHEETSSHEET 2.

avwmato a UNITED sratrgns PATENT OFFICE.

JOHN E. CHALMAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO' 'UNION'SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

[DUCK-FORMING MECHANISM Eon SEWING-MACHINES.

Specification of Letters Patent. at t May 22, 1917,

- Application filed June 11, 1915. Serial No. 33,458.

To all whom it may concern:

Be it known that I, JOHN E. OHALMAN,

a citizen of the United States, residing at Chicago, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Tuck-Forming Mechanism for Sewing-Machines, of which the following is a description, reference being bad to the accompanying drawing and to the figures of reference marked thereon.

' The invention relates to new and useful improvements in a tuck forming mechanism for sewing machines, and more particularly to a tuck forming mechanism of the charac-' ter shown in the Woodward and McNeil Patent 821,774, granted May29th, 1906.

An object of the invention is to provide means for holding the fabric properly positioned around the tuck forming ribs while the presser foot is lifted "through the action of the feed dog thereon for the feeding stroke. 1

A further object of the invention is to provide a device of the above character wherein the tucks are formed in the fabric by spaced ribs cooperating with grooves in the presser foot with yielding means for holding the fabric continuously on the work support in advance of the presser foot and between the ribs which project in front of the presser foot to assist in the initial form-.

ing of the tucks.

These and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

In the drawings which show by way of illustration one embodiment of the inventl0Il,-.

Figure 1 is aperspective view of a portion of a sewing machinehaving my improvements applied thereto;

Fig. 2 is a transverse vertical sectional view through the same, showing the feed dog positioned for its return stroke;

Fig. 3 is a detail in vertical section through the work support, showing the .presser foot, the needles and the feed dog in raised position for feeding the material;

Fig. 4 is a longitudinal vertical section through the presser foot and the work support, showing the needles in front elevation;

Fig. 5 is a detail in vertical section showing the fabric held on the work support by the auxiliary pressing member;

Fig. 6 is a detail showing diagrammatically the manner of forming the tucks in the material;

Fig. 7 is a bottom plan view of the presser foot; and

Fig. 8 is a top plan view of the throat plate, also showing the feed dog.

The machine to which my improvements are applied is shown in a general way in the Woodward and McNeil patent, above referred to, and consists of a work support 1, an overhanging arm 2, in which reciprocates a needle bar 3, carrying two pairs of needles 4-4 and 5-5. A looper 6 cooperates with the'needles 4-4, which are slightly in advance of the needles 55 and a. looper 7 oooperates with the needles 55.

The material is held on the work support by aupresser foot 8, carried by a presser bar 9. A feed dog 10 cooperates with the presser foot for feeding the material. Said feed dog 10 is carried by a feed bar 11, which is raised and lowered by an eccentric 12,"and said feed bar is reciprocated by a feed rocker 13 in a manner well known in this art.

As clearly shown in Fig. 4:, thepresser foot is formed with two longitudinal grooves 14 and 15. These grooves extend from end to end of the presser foot and centrally through the needle openings 16 and 1 through which the pairs of needles respectively operate. The throat plate of the machine is provided with ribs 18 and 19, which are adapted to extend respectively into the grooves 14 and 15. These ribs, as clearly shown in Fig. 8, extend into the needle openings 20 and 2] in the throat plates for the respective pairs of needles. The fabric, indicated at F in the drawings, is laid on the work support over the ribs 18 and 19, and when the presser foot is lowered so that the ,ribs extend into the grooves 14: and 15, re-

needles 44 pass on the opposite sides of the.

rib 18, forming the needle loops L -4:, which are joined by a looper thread 6'. This looper thread joining the needle loops holds the fabric in the form of a tuck. The

needles 5-5 pass 011 opposite sides of the rib 19, forming the needle loops 55', which are likewise joined by a looper thread loop 7', and this looks and forms the tuck The feed dog 10 is formed with feed webs 22 and 23, which extend along the outer.

sides of the ribs from a point in front of the needles to a point in rear of the needles for feeding the material. Said feed dog also has a feeding web 24 directly in rear of the needles. There is still another feeding web 25 which engages the material between the ribs 18 and 19. These feeding webs cooperate to feed the material underneath the presser foot. I t is well known that the feed dog 10 when raised into contact with the material for feeding the same also raises slightly the presser foot and then the feed dog sliding along the underface of the presser foot carries the material and positions the same for the next stitching operation, after which the feed dog drops and is returned for the next feeding movement. The presser foot 8, therefore, during the normal feeding of the machine is intermittently raised and lowered slightly from the ribs 18 and 19 and also from the work support between the ribs.

This action of the presser foot between the ribs has in effect a sucking action which causes the material to rise from the work support and this rising of the material is apt to deform the tucks or air cords made on the machine. In order to obviate this difficulty, I have provided an auxiliary pressing member 26, which, as herein shown, is in the form of a roller carried-by a pivoted arm 27, which is forked to receive the roller and the pivot pin 28, on which the roller is journaled. Said arm at its rear end is provided with two upwardly turned lugs 29 and 30, which engage a pivot pin 31 passing through brackets 32-452 fOlll'lGd. integral with the presser foot. A spring 33 surrounds this pivot pin 31- and bears on the arm 27 so as to nor-' mally depress the roller 26. A screw 34: ex tends through the arm 27 and serves as a limiting stop to limit the downward movement of the arm 27, relative to the presser foot. This arm 27 and the stop are so positioned that. when the presser foot is flat on the material and the material on the work support, that is, when the feed dog 10* is depressed, then the roller 26 engages the material between the ribs 18 and 19 in advance of the presser foot. and yieldingly holds the material on the work support.

Said arm and stop are also so positionedthe material. \Vhen the presser foot is raised for the insertion of the material underneath the same, then the stop engages the presser foot and limits the downward movement of the arm 27, so that the arm and the presser roller carried thereby will be bodily raised from contact with the material on the work support. This facilitates the insertion of the material underneath the presser foot. During the normal feeding operation of the machine, however, this auxiliary pressing member 26 holds the material continuously against the work support, while the presser foot is being raised by the feed dog.

\Vhen the presser foot is raised from the work support through the action of the feed dogs thereon, the grooves will be raised from the ribs to a certain extent and the fabric through the sucking action of the foot may be raised from the ribs. It is found in practice, that it is very diflicult to form the ribs and the groove and position the presser foot so that these ribs will move into the grooves with equal friction against the fabric at each side of each groove and, therefore, the up and down movement of the presser foot tends to gri the fabric at one side of one rib more firm y than around the opposite rib and the result is a shifting or a lateral creeping of the tucks in the fabric which, of course, forms an irregularly placed tuck. By my improvement, however, wherein the feed dog is provided with a fabric engaging web located between the ribs, the fabric will be clamped by this section of the feed dog, firmly against the under face of the presser foot when the presser foot is raised, and this prevents the lateral creeping of the fabric.

This feed section may be located centrally between the ribs and the placing of the same at one side of the center is purely for the purpose of convenience.

The ribs 18 and 19 project some distance in advance of the presser foot, as clearly shown in Fig. 1 of the drawings. The roller 26 pressing on the fabric between the ribs holds the same continuously against the work support and this positioning of the fabric between the tucks prior to the forming of the tucks through the cooperation of the grooves in the presser foot with the ribs,

insures auniform placing of the tucks. Furthermore, this roller 26 tends to hold the fabric section between the ribs on the work support and in part overcomes the distortion of the tucks due to the up and down movements of the presser foot on the ribs. The presser foot is provided with longitudinal grooves 35 and 36 which become guiding grooves when more than two tucks are formed. For example, after having formed two tucks, when it is desired to form another pair of tucks, and space the same the same distance from the previously formed tucks as the distance between the tucks, then one 'of the previously formed tucks is run through either the groove 35 or the groove 36, which becomes a guiding groove for positioning the fabricduring the formation of the new pair of tucks.

It is obvious that minor changes in the details of construction may be made without departing from the spirit of the invention,

- as set forth in the appended claims.

Having thus described my invention, what I claim as new and-desire to secure by LettersPatent, 1s:-

1. The combination of a work support, a

feeding mechanism including a feed dog located beneath the work support, a presser foot cooperating with said feed dog, said work support having spaced ribs thereon and the presser foot having grooves cooperating with said ribs to form tucks in the fabric, stitching" mechanism for stitching the tucks, and means yieldingly engaging the material in advance of the presser foot for holding the same continuously on the work support in advance of the presser foot.

2. The combination of a work support, a feeding mechanism including a feed dog 10- cated'beneath the work support, a presser foot cooperating with said feed dog, said work support having spaced ribs thereonextending in front of the presser foot, grooves cooperating with said ribs to form tucks in the material, stitching mechanism for stitching the tucks, means carried by the presser foot and engaging the material in advance thereof for holding the material on said tuck forming ribs, and devices for yieldingly pressin said means on the work support when t e presser foot is raised through the action of the feed dog.

8. The combination of a work support, a feeding mechanism including a feed dog located beneath the work support, a presser foot cooperating with said feed dog, said work support having spaced ribs thereon extending in front of the presser foot, said presser foot having grooves cooperating with said ribs to form tucks in the material, stitching mechanism for stitching said tucks, a pivoted arm carried by the presser foot and extending forwardly therefrom, a roller' pivotally supported by said arm and cotiperating with the work support between said ribs, and means for yieldingly depressing said arm.

4. The combination of a work support, a feeding mechanism including a feed dog lo-. cated beneath the work support, a presser foot cooperating with said feed dog, said work support having spaced ribs thereon extending in front of the presserfoot, said foot having grooves cooperating with said ribs to form tucks in the material, stitching mechanism for stitching said tucks, a pivotally supported by said arm and coiiperating with the work support between said'ribs, a spring engaging'said arm and forcing the same downwardly to cause said roller to engage the material on the work support, and a stop for limiting the downward movement of said arm. 1

5. The combination of a work support, a feeding mechanism including a feed dog located beneath the work support, a presser foot cooperating with said feed dog and having grooves formed in its under face, said work support having spaced ribs thereon extending in front of the presser foot, said grooves cooperating with said ribs to form tucks in the material, stitching mechanism for stitching said tucks, a pivoted arm carried by the presser foot and extending forwardly therefrom, a roller pivotally supported by said arm and cooperating with the work support between said ribs, a spring engaging said arm and forcing the same downwardly to cause said roller to engage the material on the work support, and a stop for limiting the downward movement of said arm, said stop being adjustable.

6. The combination of a work support, a.

presser foot, said work support having spaced ribs thereon, said presser foot having grooves formed in its under face cooperating with the ribs to form tucks in the fabric, stitching mechanism for stitching the tucks and a feeding mechanism includinga feed dog having a feeding section, engaging the material between the ribs.

7. The combination of a work support, a

presser foot, said work support having spaced 'ribs thereon, said presser foot having grooves formed in its under face 0 erating with the ribs to form tucks in the abric,

gaging the material between the ribs,-and

at points outside of said ribs, each of said feeding sections having their forward ends substantially in line and at'the forward end of the presser foot. 4

9. The combination of a work support, a presser foot cooperating with said work support, said presser foot having parallel grooves formed in its under face, said work support having ribs adapted to extend into said grooves, said ribs projecting some distance in front of the presser foot, yielding support, a feed dog cooperating with the presser foot and having feed sections engaging the fabric at each side of and between the ribs adjacent the forward end of the presser foot.

10. The combination of a work support, a presser foot cooperating with said work support, said presser foot having parallel grooves formed in its under face, said work support having ribs adapted to extend into said grooves, said ribs projecting some distance in front of the presser foot, yielding means for engaging the fabric in front of the presser-footbetween said ribs for con-* tinuously holding the fabric on the work support, a feed dog cooperating with the presserfoot and having feed sections engaging the fabric at each side of and between the ribs adjacent the forward end of the presser foot, and stitch forming mechanism including pairs of needles, one pair for each rib, said needles of each pair being dis- 

